1. The Field of the Invention
This invention relates to digital computers, and more particularly, to unique apparatus and methods for blocking selected key codes, sequences of key codes, and combinations of key codes transmitted between a keyboard and a host computer.
2. The Relevant Art
Kiosks of various types and providing a wide variety of services, are currently increasing in popularity. Most kiosks operate using standard computer hardware and include some type of input device such as a keyboard. When designing a kiosk for use by the public, it is often desired to prevent customers from entering certain keys, key sequences, or key combinations from the keyboard. For example, if the input device is a standard keyboard, it may be desired to prevent a user from entering a key combination such as a “CTRL-ALT-DEL” sequence. This key sequence may enable a user of a kiosk to access shut down or reboot commands, or may allow undesired access to applications or data.
Currently, offending keys are blocked using either hardware or software. A typical hardware method is to design a keyboard that does not offer undesired keys to a user. This limits the choices available to a designer and may add expense by requiring a customized keyboard. One typical software solution is to alter drivers or system BIOS on a kiosk host computer so that undesired key codes are ignored. This solution can be impractical since a designer may then become responsible for writing and maintaining keyboard driver code for each operating system used.
Given the drawbacks of current solutions, apparatus and methods are needed to improve currently practice methods for blocking or filtering out selected key codes. Consequently, a need exists for improved apparatus and methods that block or filter out selected keys, sequences of keys, or combinations of keys that a user may input from a keyboard or other input device. What is further needed are such apparatus and methods that are easily installed with an existing keyboard and host computer without requiring modification of an operating system or installing additional applications on the host computer.
In particular, what is needed is an apparatus, physically independent from the host computer and keyboard, that may simply be inserted therebetween to monitor combinations and sequences of key presses, in addition to keys pressed alone, which would provide the desired key code filtration. Accordingly, it would also be an advance in the art to provide a filtration device that could be easily reprogrammed or updated to add, delete, or modify the set of selected keys codes to be blocked.